Every time I use my countersink bit, it creates a hexagonal hole.
I've tried a hand drill, an electric drill, drilling fast, drilling slow, soft pressure, firm pressure - virtually every time it will create a hexagonal hole. Of the 12 I drilled yesterday, only one was round, and that felt like it was due to that being an abnormally soft area in the wood.
Is it the design of the bit? I'm sure the one my dad used when I was a kid had many more vanes.
Or is it something I'm doing wrong?
Basically, how do I get a circular countersink?
Tried out some of the suggested solutions last night, from L-R is:
- Countersink before hole
- Large standard drill bit
- Hand-turned countersink
Countersinking before drilling the whole is clearly the best, at least for the plywood I'm using. The hand-turned bit could potentially work with a bit more care too; the hole itself is nice and round. Maybe needs a sharper bit.
(Apologies for picture quality)
UPDATE: I had to do a couple more last night, but forgot to countersink first; the hand-turned technique worked really well in the painted plywood, although it took care to keep it centred.